1. Field of the Invention
This invention relates to a method for the production of 1,3-thiazolidin-2-ones. More particularly, it relates to a method for the production of 1,3-thiazolidin-2-one from 1,3-thiazolidines.
2. Description of the Prior Art
1,3-Thiazolidin-2-one are useful as intermediates for medicines and agricultural pesticides. To date, the following methods have been proposed for the production of these compounds.
(A) A method disclosed in "Journal of American Chemical Society," vol 78, page 5350 (1956), which effects the production by fusing cysteamine hydrochloride and urea and allowing them to react with each other.
(B) A method disclosed in Japanese Patent Laid-Open SHO 62(1987)-84,067, which attains the production by causing 2-aminoethyl sulfate or 2-chloroethyl amine hydrochloride to react with carbonyl sulfide in the presence of a deacidifying agent.
(C) A method disclosed in Japanese Patent laid-Open SHO 61(1986)-30,580, which obtains the production by causing 1,3-oxazolidin-2-one to react with hydrogen sulfide under application of pressure.
(D) A method disclosed in Japanese Patent Laid-Open SHO 50(1975)-117,772, which accomplishes the production by cysteamine to react with carbon monoxide in the presence of selenium and a tertiary amine.
The conventional methods mentioned above, however, have various drawbacks of their own. The method of (A) has the problem of disposing of an inorganic salt by-produced in a large amount by the reaction and entails the disadvantage that the reaction product necessitates a complicate treatment for purification. The method of (B), similarly to that of (A), entails the problem of disposal of a by-produced inorganic salt and the disadvantage that the raw material, carbonyl sulfide, is not easily obtained commercially. The method of (C) has the disadvantage that hydrogen sulfide, a noxious substance, undergoes the reaction under application of pressure and the reaction requires use of 1,3-oxazolidin-2-one, a compound not readily obtained as a raw material. Then, the method of (D) inevitably necessitates use of expensive selenium as a catalyst. Because of the various drawbacks described above, these conventional methods are not advantageous for commercial production of 1,3-thiazolidin-2-ones.
An object of this invention, therefore, is to provide a novel method for the production of 1,3-thiazolidin-2-ones.
Another object of this invention is to provide an economic method for the production of 1,3-thiazolidin-2-ones.